Taking Your Child's Temperature

If you suspect that your child has a fever, it's extremely important that you take your child's temperature properly. Once you have an accurate reading, you'll be able to determine if your child's temperature is high enough for you to give him fever-reducing medication or to call the pediatrician.

There are several different methods of taking a child's temperature. Each one has positives and negatives. Which one you use will depend on your child's age and your personal preferences.

Mercury thermometers used to be a common means of taking a child's temperature. This is no longer recommended. In fact, the American Academy of Pediatrics suggests that parents remove all mercury thermometers from their homes to eliminate the potential danger of being exposed to the toxin.

Here's the lowdown on the various acceptable methods of taking your child's temperature:

Rectal Reading

When to use it

A rectal reading is recommended for babies 3 years of age and younger -- it provides the most accurate readings for that age group. Rectal readings are also recommended for older children who aren't able to have their temperature taken orally because of continual coughing or a too-congested nose.

How to do it

1. Read the directions that came with the thermometer so you'll know which beep (or series of beeps) is a sign that the thermometer is finished reading. Turn it on and check that the screen is clear of any previous readings.

2. Clean the tip of the thermometer with rubbing alcohol or soap and water. Then rinse it with cool water. If you have one available, cover the thermometer with a disposable single-use plastic sleeve.

3. Lubricate the tip of the thermometer with a water-soluble jelly.

4. Place your baby across your lap, face down. Don't forget to support his head. For an older child or a very squirmy baby, lay him down on a firm, flat surface (such as a changing table) or on top of a blanket on the floor.

5. Press the palm of one hand firmly against your baby's lower back to hold him still. With the other hand, turn on the thermometer switch and insert the thermometer about 1/2 inch into your baby's anus. Always stop if you feel resistance.

6. Hold the thermometer in place loosely with two fingers, keeping your hand cupped around your child's bottom, until you hear the beep.

7. Remove the thermometer to check the digital reading. Record the temperature and the time of day it was taken in case you need to inform the pediatrician.

8. If you used a disposable plastic sleeve, discard it right away. Clean the thermometer, replace it in its case, and mark the case "rectal" -- it's easy to grab an oral thermometer by accident if you're tired or it's dark in the room.

Oral Reading

When to use it

Once your child is 4 or 5 years of age, this is usually the most preferable method of taking his temperature. It offers a more accurate temperature than ear or axillary readings.

How to do it

1. Read the directions that came with the thermometer so that you know which beep (or series of beeps) is a sign that the thermometer is finished reading. Turn it on and check that the screen is clear of any previous readings.

2. Clean the thermometer with lukewarm soapy water or rubbing alcohol. Rinse with cool water. Cover the thermometer tip with a disposable plastic shield, if you have one available.

3. Make sure that your child's mouth is clear of candy, gum, or food. If your child has recently had a hot or cold drink, wait 15 minutes before taking her temperature.

4. Place the thermometer tip under your child's tongue, towards the back of his mouth, and tell her to close her lips around it. Remind her not to bite the thermometer or talk while the thermometer is in her mouth. Make sure she's breathing normally through her nose.

5. Hold it in place for about one minute, until you hear the beep or series of beeps that indicates that the reading is complete.

6. Remove the thermometer to check the digital reading. Record the temperature and the time of day it was taken in case you need to inform the pediatrician.

7. If you used a disposable plastic sleeve, discard it right away. Clean the thermometer, replace it in its case, and mark the case "oral" -- it's easy to grab a rectal thermometer by accident if you're tired or it's dark in the room.

Axillary (Armpit) Reading

When to use it

This method is acceptable for babies over 3 months of age. While it's certainly preferable (for both mother and baby) to a rectal reading, the results are usually not as accurate. If you're squeamish about taking your infant's or young child's temperature rectally, the axillary method is the next best choice.

How to do it

1. You can use either a rectal or oral thermometer. Read the directions that came with the thermometer so that you know which beep (or series of beeps) is a sign that the thermometer is finished reading. Turn it on and check that the screen is clear of any old readings.

2. Prepare the thermometer by washing it in cool (not hot) soapy water or rubbing alcohol.

3. Remove your child's shirt and undershirt. Make sure that the thermometer will only touch skin and not clothing.

4. Insert the thermometer in your child's armpit. Hold your child's arm tightly across his chest to keep the thermometer in place until you hear the beep or series of beeps.

5. Remove the thermometer to check the digital reading. Record the temperature and the time of day it was taken in case you need to inform the pediatrician.

6. Be aware that axillary readings may be a degree or two below oral or rectal readings. If your child's temperature is above 102 degrees, it's recommended that you take it again orally (if your child is 3 years or older) or rectally for a more accurate reading.

Tympanic (Ear) Reading

When to use it

This fairly new method of taking a baby's temperature (which can be used on babies 3 months and older) also seems to be the one that parents prefer most. It provides quick results -- in just a few seconds -- and generally keeps kids feeling relaxed and comfortable. However, there are a few drawbacks: tympanic thermometers are more expensive than oral or rectal thermometers and don't provide readings that are quite as accurate.

How to do it

1. Read the directions that came with the thermometer so that you know which beep or series of beeps is a sign that the thermometer is finished reading.

2. Make sure your child's ear doesn't have excess earwax in it. If so, try cleaning it with a cotton swab without entering the ear canal.

3. Gently put the end of the thermometer in your baby's ear and press the "start" button.

4. Remove the thermometer when you hear the beep or series of beeps (which should be within seconds).

5. Remove the thermometer to check the reading. Record the temperature and the time of day it was taken in case you need to inform the pediatrician.

6. Be aware that tympanic readings have a tendency to be low. If your child's temperature is above 102 degrees, it's recommended that you take it again orally (if your child is 3 years or older) or rectally for a more accurate reading.

Sources: American Medical Association; American Academy of Pediatrics; The Nemours Foundation

All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.